Key-Value Storage (@microfn/kv)

@microfn/kv

The @microfn/kv module allows you to store and retrieve data that persists across function executions. It’s perfect for caching, user preferences, session data, and any state that needs to survive between runs.

Import

import kv from "@microfn/kv";

Quick Snippet

// Write to the key-value store
await kv.set("my-key", { message: "Hello World" });

// Read from the key-value store
const value = await kv.get("my-key");

Examples

Here are a few useful things you can do with @microfn/kv:

1. Cache an API response

Avoid hitting external APIs on every request by caching responses for a specific duration.

export async function main({ url }) {
  const key = `cache:${url}`;
  const cached = await kv.get<{ data: any; ts: number }>(key).catch(() => null);

  // Return cached data if it's less than an hour old
  if (cached && Date.now() - cached.ts < 3_600_000) {
    return { ...cached, fromCache: true };
  }

  // Fetch fresh data and cache it
  const res = await fetch(url);
  const data = await res.json();
  await kv.set(key, { data, ts: Date.now() });

  return { data, fromCache: false };
}

2. Implement a simple counter

Track hits for a specific route or event.

export async function main({ route }) {
  const key = `hits:${route}`;
  const currentHits = (await kv.get<number>(key).catch(() => 0)) + 1;
  await kv.set(key, currentHits);
  return { route, hits: currentHits };
}

3. Store user preferences

Save user-specific settings that can be retrieved later.

export async function main({ userId, prefs }) {
  const key = `user:${userId}:prefs`;
  await kv.set(key, prefs);
  const savedPrefs = await kv.get(key);
  return { success: true, saved: savedPrefs };
}